Projection zoom lens and camera

ABSTRACT

A projection zoom lens assembly for a digital cinema projection system includes three optical groups. A first optical group includes one or more wide angle lenses for projecting digital cinema images. A second optical group includes a set of zoom optical groups each comprising two or more lenses, including a first independently movable zoom group, a second independently movable zoom group, and a third zoom group. A third optical group includes multiple lenses for receiving images for projection.

PRIORITY

This application claims priority to U.S. provisional patent applicationNo. 62/146,130, filed Apr. 10, 2015, which is incorporated by reference.

BACKGROUND

For more than twenty years, DLP projection display systems have offeredsmooth (at 1080p resolution), jitter-free images with excellent geometryand grayscale linearity and usually excellent ANSI contrast. The lightfrom the projected image is not inherently polarized. New LED and laserDLP display systems more or less eliminate the need for lampreplacement. DLP offers affordable 3D projection display from a singleunit and can be used with both active and passive 3D solutions.

DLP systems are typically lighter weight than LCD and plasmatelevisions. Unlike their LCD and plasma counterparts, DLP screens donot rely on fluids as their projection medium and are therefore notlimited in size by their inherent mirror mechanisms, making them idealfor increasingly larger high-definition theater and venue screens. DLPprojectors can process up to 7 separate colors, giving them a wide colorgamut.

However, rear projection DLP TVs are not as thin as LCD or plasmaflat-panel displays (although approximately comparable in weight).Dithering noise may be noticeable, especially in dark image areas. Newerchip generations have less noise than older ones. Error-diffusionartifacts are sometimes caused by averaging a shade over differentpixels, since one pixel often cannot render the shade exactly. Responsetime in video games may be affected by upscaling lag. While HDTVstypically have some lag when upscaling lower resolution input to theirnative resolution, DLPs are commonly reported to have longer delays.Newer consoles such as the Wii do not have this problem as long as theyare connected with HD-capable cables.

DLP images that are displayed have to be viewed at a reduced viewingangle as compared to direct-view technologies such as CRT, plasma, andLCD. DLP systems may use more electricity, and generate more heat, thancompeting technologies. Some people may be able to observe a phenomenonin which the projected contents appear to be cycling through its colorsfor the duration of the presentation. This is most easily seen by usinga camera's ‘live view’ mode on projected content.

It is desired to have a projection zoom lens assembly that offersenhanced high resolution projection of images with low distortion andlow chromatic aberration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plot of transmission versus wavelength for an exampleprojection lens assembly in accordance with certain embodiments.

FIG. 2 schematically illustrates a side view of a projection lensassembly outline and mounting in accordance with certain embodiments.

FIGS. 3A-3C schematically illustrate side views of optical elements of aprojection zoom assembly for three relative positions of two movablezoom lens groups in accordance with certain embodiments.

BRIEF DESCRIPTION OF THE TABLES

Table 1 includes object specifications for an example projection zoomlens assembly in accordance with certain embodiments.

Table 2 includes imaging details for an example projection lens assemblyin accordance with certain embodiments.

Table 3 includes projected resolution details for an example projectionlens assembly in accordance with certain embodiments.

Table 4 includes illumination details for an example projection lensassembly in accordance with certain embodiments.

Table 5 includes operating details for an example projection lensassembly in accordance with certain embodiments.

Table 6 includes an optical prescription for an example projection lensassembly in accordance with certain embodiments.

Table 7 includes example specification data for a projection lensassembly in accordance with certain embodiments.

Table 8 includes example aperture data and edge definitions for aprojection lens assembly in accordance with certain embodiments.

Table 9 lists refractive indices for certain glasses that may be used incertain lenses in an example projection lens assembly in accordance withcertain embodiments.

Table 10 includes five example zoom positions of an example projectionlens assembly in accordance with certain embodiments.

Table 11 includes zoom characteristics of the five zoom positions ofTable 10 for an example projection lens assembly in accordance withcertain embodiments.

Table 12 includes example imaging characteristics of a projection lensassembly in accordance with certain embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A projection zoom lens assembly is provided for a digital cinemaprojection system. A first optical group includes one or more wide anglelenses for projecting digital cinema images. A second optical groupincludes a set of zoom optical groups each comprising two or morelenses, including a first movable zoom group, a second movable zoomgroup, and a fixed zoom group. A third optical group includes multiplelenses for receiving images for projection.

The first movable zoom group may be movable relative to each of thefirst and third optical groups and the fixed zoom group. The secondmovable zoom group may be movable relative to the first movable zoomgroup, the first and third optical groups, and the fixed zoom group.

The first optical group includes a first lens having a largest diameteramong the lenses of the projection zoom lens assembly. The first opticalgroup may include a second lens having a second largest diameter amongthe lenses of the projection zoom lens assembly. Lenses of the secondand third optical groups may have approximately a same diameter smallerthan those of the first and second lenses of the first optical group.

The second movable zoom group may include an aperture stop. The aperturestop may be disposed between a doublet and a singlet of the secondmovable zoom group.

The third optical group may include a doublet or a quasi-doublet orboth. A quasi-doublet is referred to herein as a pair of closely-spacedlenses that are not in contact over their entire radius but may be incontact or approximately so at one or more radial locations. The thirdoptical group may include a meniscus and a biconvex lens.

Each of the zoom optical groups may include a singlet spaced from adoublet or a quasi-doublet.

A first adjustable spacing may be defined between the first opticalgroup and the first movable zoom group. A second adjustable spacing maybe defined between the first movable zoom group and the second movablezoom group. A third adjustable spacing may be defined between the secondmovable zoom group and the fixed zoom group.

The projection zoom lens assembly may exhibit axial chromaticaberrations less than 20 microns.

The projection zoom lens assembly may exhibit lateral chromaticaberrations less than 0.75 pixels.

The projection zoom lens assembly may exhibit lateral chromaticaberrations less than 0.5 pixels.

The projection zoom lens assembly may exhibit distortion at 0.75 fieldof less than 2.5%.

The projection zoom lens assembly may exhibit distortion at 0.95 fieldof less than 2.0%.

The projection zoom lens assembly may exhibit a throw ratio rangebetween 0.8-1.1.

The projection zoom lens assembly may exhibit a color transmissiondifferential of less than 8%.

The projection zoom lens assembly may exhibit a total light transmissionof greater than 90%.

The projection zoom lens assembly may exhibit a focus drift of less than5 microns/20° C.

The projection zoom lens assembly may be configured to focus frominfinity to 25 feet.

The projection zoom lens assembly may be configured such that arotational torque of the projection zoom lens is less than 0.5 N-m.

A digital cinema projection system is also provided that includes arelay lens assembly and a projection zoom lens assembly as describedabove or below herein.

A zoom lens assembly in accordance with certain embodiments may projecta relayed image of DLP panels onto a large format screen to create animmersion cinema experience. The zoom lenses may be matched so that incertain embodiments the images from multiple channels and/or multiplepanels can be overlaid.

A DLP Cinema Projection Zoom Lens assembly is described with referenceto accompanying drawings and tables for use in the Digital CinemaMarket.

A projection system in accordance with certain embodiments may includethe following two modules: (a) an optical relay component, e.g., a lens,such as a single 1× relay lens; and (b) an optical zoom component, e.g.,including two wide zoom projection lenses. This specification describesexamples of a zoom lens in accordance with certain embodiments indetail. The projection system may be used within a 1.38″ diagonalenhanced 4K DLP imaging chip and may be used within 3D Digital Cinemaapplications. Both the relay and zoom have a sufficient large field tocover the 4K DLP panel with added offset. The throw ratio range of theprojection zoom lens specified herein may in certain embodiments be in arange between 0.8-1.1.

Projection Lens Optical Design Type

The optical design type may include a dioptric projection zoom withmultiple moving groups and a constant f/number thru zoom.

Object (Intermediate Image) Specifications

The object specifications for an example projection zoom in accordancewith certain embodiments are listed below in Table 1.

TABLE 1 Panel Nominal Units/Notes Pixel pitch  7.6 Um Resolution 4096 ×2160 Pixels Pixel aspect ratio    1:1 width:height each pixel Panelaspect ratio 1.896:1 width:height full panel Intermediate image size35.2 mm diagonal

Imaging

The imaging details for an example projection zoom in accordance withcertain embodiments are listed below in Table 2.

TABLE 2 Example Embodiment Characteristics Nominal Units/Notes Designwavelengths (weights) 460 (1), 546 (2), Nm 620 (1) Nominal throwdistance 20 meters Throw distance range 15-45 meters Nominal screenwidth 22 meters (or 73 ft) Throw ratio 0.8-1.1 zoom screen width/throwEFL mm, zoom, imaging requirements best effort  Operating range24.9-31.9 outsideoperating range  Total range with over-travel 24.0-36.0F-number 2.5 Pupil apodization uniform Field size 45.25 mm. Includes+/−50% vertical shift. Horizontal shift is 0% at maximum verticaloffset. BFL Minimum 5 mm air Equivalent to back working distance (BWD).Exit pupil location (screen side) <50 mm, measured from vertex of lenssurface nearest the screen, reverse ray trace Focus adjustment +/−3.0mm, externally accessible adjustment Telecentricity +/−1.0 degree, max,full field, tlu-u zoom Distortion, 0.75-field <2.5% Chief ray relativeto paraxial ray position, full field, over operating zoom range.Distortion, 0.95-field <2.0% Chief ray relative to paraxial rayposition, full field, over operating zoom range. Matched pair distortiondifference |D_(distoration)| < 0.11% Better than 2 pixel overlaprequired in corners, after zoom, focus, and offset adjustments. Motionof internal compensation group is also allowed. Lateral color R-G,0.75-field <0.50 pixel, max Lateral color R-G, 0.95-field <0.50 pixel,max Lateral color B-G, 0.75-field <0.75 pixel, max Lateral color B-G,0.95-field <0.75 pixel, max Lateral color B-R, 0.75-field <0.75 pixel,max Lateral color B-R, 0.95-field <0.75 pixel, max Axial color, R-G|D_(R-G)| < 20 um, relative to G, evaluated at 0.6 pupil for B = 460 nm,G = 546 nm, R = 620 nm, 20 m image distance Axial color, B-G |D_(B-G)| <20 um, relative to G, evaluated at 0.6 pupil for B = 460 nm, G = 546 nm,R = 620 nm, 20 m image distance Individual R, G, B MTF Target 1 >95% 10lp/mm, 0-0.9 field, <T&S> by design, (Tangential/Sagittal) at a singlefocal plane for R, G, B Individual R, G, B MTF Target 2 >84% 30 lp/mm,0-0.9 field, <T&S> by design, (Tangential/Sagittal) at a single focalplane for R, G, B Individual R, G, B MTF Target 3 >50% 66 lp/mm, 0-0.9field, <T&S> by design, (Tangential/Sagittal) at a single focal planefor R, G, B Individual R, G, B MTF Target 4 >20% 100 lp/mm, 0-0.9 field,<T&S> by design, (Tangential/Sagittal) at a single focal plane for R, G,B Image shift, vertical +/−50% screen height Projected Resolution Table3 Table 3 Transmission Table 4 Table 4

Projected Resolution Details

Projected resolution details for an example projection zoom inaccordance with certain embodiments are provided in Table 3.

TABLE 3 Resolution Requirements Nominal Units/Notes Axis 150 lp/mmVisual projection test at 12 m 0.3 Field 125 lp/mm Visual projectiontest at 12 m 0.6 Field 100 lp/mm Visual projection test at 12 m 0.9Field  75 lp/mm Visual projection test at 12 m 100 lp/mm best effort

Illumination Details

The screen illumination details for an example projection zoom inaccordance with certain embodiments are listed in Table 4.

TABLE 4 Illumination Requirements Nominal Units/Notes Relativeillumination >75% 0.95 field Total light transmission >90% average over440-660 nm Color transmission  <5% B = 460 nm, G = 546 nm, differential,R-G, B-G R = 620 nm Color transmission  <8% B = 460 nm, G = 546 nm,differential, B-R R = 620 nm

A transmission curve is provided in FIG. 1, including a plot oftransmission versus wavelength for a projection zoom lens assembly inaccordance with certain embodiments.

Operating Details

Operating details for an example projection zoom in accordance withcertain embodiments are listed in Table 5.

TABLE 5 Operating Requirements Nominal Units/Notes ANSI contrast >400:1reference only Luminous flux range 10,000-40,000 lumens, reference,laser compatible Environmental operating 20 +15/−5 C. reference tempFocus drift <5 um/20 C., over environmental operating range, per thermalsimulation Boresight <0.25 deg, line of sight error to center of displayrelative to mechanical datums Decenter <0.50 mm, optical axis relativeto mechanical datums

Mechanical Details

FIG. 2 schematically illustrates outline and mounting details for anexample projection zoom lens assembly including the location of the zoomand focus rings, relevant mechanical dimensions, and flange focaldistance details. At infinite conjugates, the flange focal distance ofthe projection lens assembly may be factory set in certain embodimentsat a distance of 151.50 mm±0.50 mm.

Optical Details

FIGS. 3A-3C schematically illustrate side views of optical elementswithin three optical groups G1, G2 and G3 from closest to furthest fromthe projection end of an example projection zoom assembly for threerelative positions of two movable zoom lens groups ZG1 and ZG2 and afixed zoom lens group ZG3 in accordance with certain embodiments. Table6 includes an optical prescription for the example projection zoomassembly of FIGS. 3A-3C, including the radius of curvature of eachoptical surface of the example projection zoom lens assembly, thethickness of each lens, the spacings between lenses, and the glass typefor each lens. Each of the projection zoom assemblies of FIGS. 3A-3Cinclude from closest to furthest from the projection end, the firstoptical group G1 that includes four lenses in this example embodiment, asecond optical group G2 that includes nine lenses in this exampleembodiment, and a third optical group G3 that includes four lenses inthis example embodiment. Each lens group G1, G2 and G3 may include moreor fewer than these respective numbers of lenses.

The first optical group G1 includes, from closest to further from theprojection end, a first, second and third lenses each having a largerdiameter than any lens to its right in the side views of FIGS. 3A-3C.Each of these first three lenses is convexo-planar orconvexo-quasi-planar or convexo-concave. A fourth lens of the firstoptical group has a diameter that is approximately the same as thediameters of other lenses of the optical assembly within the second andthird lens groups G2, G3. The first optical group is configured toproject digital cinema images at a wide field, e.g., 90 degrees or more.

The second optical group G2 includes, from closest to furthest from theprojection end, a first zoom group ZG1, a second zoom group ZG2, and athird zoom group ZG3. In this example, the first zoom group ZG1 includesa singlet and a quasi-doublet, the second zoom group ZG2 includes asinglet, an aperture stop and a doublet or quasi-doublet, and the thirdzoom group ZG3 includes a doublet or quasi-doublet and a singlet, fromclosest to furthest from the projection end of the projection zoomassembly.

The third optical group G3 includes, from closest to furthest from theprojection end, a doublet or quasi-doublet spaced from a quasi-doubletthat includes a concavo-convex meniscus and a bi-convex lens. Images areprovided to the projection system from the image plane IM.

The first and second zoom groups ZG1 and ZG2 are movable in the exampleof FIGS. 3A-3C relative to the first and second groups G1 and G2 andrelative to the third zoom group ZG3 which is fixed in this example. Thefirst and second zoom groups ZG1 and ZG2 are also movable relative toeach other. Thus, a first spacing S1 is defined between the first groupG1 and the first zoom group ZG1, a second spacing S2 is defined betweenthe first and second zoom groups ZG1 and ZG2, and a third spacing S3 isdefined between the second and third zoom groups ZG2 and ZG3. Each ofthe spacings S1, S2 and S3 is adjustable in the example of FIGS. 3A-3C.

In the example of FIGS. 3A, 3B and 3C, the spacing S1 is larger in FIG.3A than in either of FIG. 3B or 3C, and the spacing S1 is larger in FIG.3B than in FIG. 3C. The first movable zoom group ZG1 is positionedcloser to the first optical group G1 in FIG. 3C than in either of FIG.3A OR 3B, and the first movable zoom group ZG1 is positioned closer tothe first optical group G1 in FIG. 3B than in FIG. 3A.

Also, the spacing S2 is larger in FIG. 3A than in either of FIG. 3B or3C, and the spacing S2 is larger in FIG. 3B than in FIG. 3C. The secondmovable zoom group ZG2 is positioned closer to the first movable zoomgroup ZG1 in FIG. 3C than in either of FIG. 3A or 3B, and the secondmovable zoom group ZG2 is positioned closer to the first movable zoomgroup ZG1 in FIG. 3B than in FIG. 3A.

Also, the spacing S3 is larger in FIG. 3C than in either of FIG. 3A or3B, and the spacing S3 is larger in FIG. 3B than in FIG. 3A. The secondmovable zoom group ZG2 is positioned closer to the third zoom group ZG3in FIG. 3A than in either of FIG. 3B or 3C, and the second movable zoomgroup ZG2 is positioned closer to the third zoom group ZG3 in FIG. 3Bthan in FIG. 3C.

FIGS. 3A-3C demonstrate that the first movable zoom group in thisexample embodiment is independently movable relative to the lens groupsG1, ZG2, ZG3 and G3. FIGS. 3A-3C also demonstrate that the secondmovable zoom group in this example embodiment is independently movablerelative to the lens groups G1, ZG1, ZG3 and G3. While in certainembodiments, the lens groups G1, ZG3 and G3 may be fixed, one or more ofthe lens groups G1, ZG3 or G3 may be movable and/or one or more subsetsof any of the lens groups G1, ZG1, ZG2, ZG3 or G3 may be movabletranslationally and/or rotationally. In addition, one or more lenses maybe replaceable with one or more respective replacement lenses having oneor more different optical properties.

ZOOM MECHANISM Drive Mechanism

The projection lens zoom operation may be achieved via rotation of thezoom ring.

Rotation Direction

The rotation angle of the projection lens to achieve the entire zoomrange may be 90°. The rotation direction from short focal length to longfocal length may be clockwise when viewed from the projector side.

Rotational Movement

The rotational movement of the projection lens may be smooth inoperation without rattles, squeaks, or binding.

Rotational Torque

The rotational torque of the projection lens zoom function in certainembodiments may be less than ≦0.5N-m.

Zoom Range Scale

In certain embodiments, there are no markings on the zoom ring of theprojection lens.

Zoom Gear Ring

The projection lens zoom may include a gear ring in certain embodiments.

FOCUS MECHANISM Focusing System

The projection lens may have a front group focus via a focus helix.

Operating Focusing Range

The projection lens may have the ability to focus from infinity(collimated) down to 25 feet (7.6 meters).

Rotational Direction

The focus rotation angle of the projection lens assembly may be 180°over the operating range. Rotation direction for infinity to NEAR may beclockwise when viewed from the projector side.

Rotational Movement

The rotational movement of the projection lens may be smooth inoperation without rattles, squeaks, or binding.

Rotational Torque

The rotational torque of the projection lens zoom function may incertain embodiments be less than ≦0.5N-m.

Focus Gear Ring

The projection lens focus may include a gear ring.

Projection Lens Assembly Weight

The weight of the projection lens assembly without motors, bracket, ormounting flange may be less than 7 lbs in certain embodiments.

RELIABILITY Shock

A projection lens assembly in accordance with certain embodiments may beconfigured such that it does not suffer from degradation in performanceafter exposure to a shock of 70G (980 m/s) of half sine wave impact whenthe lens is contained in the minimum unit packaging condition. Theimpacts maybe applied in six directions one at a time (six impactstotal).

Vibration

The projection lens assembly in accordance with certain embodiments maybe configured such that it does not suffer degradation in performanceafter exposure to sine wave vibration of frequencies ranging from 20 Hzto 60 Hz in steps of 4 Hz. The vibration may be applied for 2 minutes ateach frequency with amplitude of 1 mm and applied on the threeorthogonal axes with a maximum duration of 20 minutes in one direction.

Low Temperature Storage

A projection lens assembly in accordance with certain embodiments may beconfigured such that it does not suffer degradation in performance afterbeing stored at −40° C. for a period of 24 hours.

High Temperature Storage

A projection lens assembly in accordance with certain embodiments may beconfigured such that it does not suffer degradation in performance afterbeing stored at +70° C. for a period of 24 hours.

High Temperature and High Humidity Storage

A projection lens assembly in accordance with certain embodiments may beconfigured such that it does not suffer degradation in performance afterbeing left under ambient temperature for 8 hours subsequent to storageat +50° C. and with 90% humidity for 240 hours.

Operating Temperature

A projection lens assembly in accordance with certain embodiments isconfigured to be capable of normal performance over an operatingtemperature range of 20° C. to 35° C.

Cemented Optical Interfaces

In certain embodiments, there are no cemented interfaces allowed in theprojection lens.

Operating Humidity

Over the operating temperature range, the projection lens assembly maybe capable of normal performance over an operating humidity range of 20%to 60%.

Cosmetic Quality

The outer lens barrel may be considered a non-decorative or “Class B”and inspected per the definition and criteria below.

The projection lens outer metal may be inspected at a distance of 457 mm(18″) and each section viewed for a maximum of four seconds. Thelighting condition may be in accordance with CIE Standard Illuminant Awith approximately 80-120 foot candles illuminating the part. The lightsource may be diffuse in certain embodiments. The projection lensassembly may be configured to be unpacked, handled, inspected andrepacked using suitable gloves that will not stain the finish of thelens due to any finger oils present. The projection lens assembly may beconfigured such that it ought not be placed on a hard surface or beallowed to sit in an open area for more than 30 minutes beforeinspection. Lenses may be configured such that they ought not be stackednext to each other unless suitable separation and protection such asplastic separators are in place.

TABLE 6 Example Optical Prescription WFOV DLP Zoom (25 mm, f/2.5, 45 mm)RDY THI RMD GLA CCY THC GLC >OBJ: INFINITY 12192.000000 100 100 1:110.00000 12.875000 SLAL18_OHARA 100 100 SLB: “G1” 2: 288.50000 0.252000100 100 3: 104.25000 2.800000 SNPH1_OHARA 100 100 4: 37.67500 15.356000100 100 5: 122.62000 2.800000 SPHM52_OHARA 100 100 6: 43.47500 11.522000100 100 7: −1160.00000 2.800000 SPHM52_OHARA 100 100 8: 65.7000012.196000 100 100 9: INFINITY 21.101220 100 100 SLB: “ZCT1” 10:250.00000 7.500000 SNBH53_OHARA 100 100 SLB: “ZG1” 11: −134.3500027.261000 100 100 12: 242.00000 2.800000 SFPL51_OHARA 100 100 13:47.35000 4.890000 100 100 14: 141.60000 5.000000 SNPH1_OHARA 100 100 15:−2000.00000 17.305000 100 100 16: INFINITY 14.574566 100 100 SLB: “ZCT2”17: 86.50000 9.180000 SFPL51_OHARA 100 100 SLB: “ZG2” 18: −73.100004.150000 100 100 STO: INFINITY 4.923000 100 100 20: 2000.00000 2.500000SNBH5_OHARA 100 100 21: 50.00000 1.409000 100 100 22: 56.20000 10.000000SFPL51_OHARA 100 100 23: −81.82000 2.677000 100 100 24: INFINITY8.007804 100 100 SLB: “ZCT3” 25: −45.70000 2.800000 SNBH52_OHARA 100 100SLB: “ZG3” 26: 480.00000 0.491000 100 100 27: 298.00000 8.927000SFPL51_OHARA 100 100 28: −56.84000 2.998000 100 100 29: INFINITY2.258540 100 100 SLB: “ZCT4” 30: 69.00000 9.675000 SFPL51_OHARA 100 100SLB: “G2” 31: −196.25000 0.448000 100 100 32: 50.00000 12.040000SFPL51_OHARA 100 100 33: −116.00000 0.250000 100 100 34: −152.000002.800000 SNBH52_OHARA 100 100 35: 40.50000 30.210000 100 100 36:−29.45000 2.800000 SLAH66_OHARA 100 100 37: −43.65000 0.253000 100 10038: 79.37000 8.920000 SLAL18_OHARA 100 100 39: −140.25000 7.506000 100100 SLB: “LAST” IMG: INFINITY 0.000000 100 100

TABLE 7 Example Specification Data FNO 2.50000 DIM MM WL 620.00 546.00460.00 REF 2 WTW 1 2 1 XIM 0.00000 0.00000 0.00000 0.00000 YIM 0.0000011.31000 16.96500 22.62000 WTF 1.00000 1.00000 1.00000 1.00000 VUX0.00000 −0.06249 −0.13627 −0.23749 VLX 0.00000 −0.06249 −0.13627−0.23749 VUY 0.00000 −0.21599 −0.53249 −1.11952 VLY 0.00000 −0.19973−0.50037 −0.50009 POL N

TABLE 8 Example Aperture Data/Edge Definitions CA CIR S1 55.000000 CIRS2 52.750000 CIR S3 43.750000 CIR S4 32.500000 CIR S5 32.000000 CIR S628.000000 CIR S7 28.000000 CIR S8 27.000000 CIR S10 27.850000 CIR S1127.850000 CIR S12 23.500000 CIR S13 22.500000 CIR S14 22.500000 CIR S1522.500000 CIR S17 22.000000 CIR S18 22.000000 CIR S20 20.400000 CIR S2120.400000 CIR S22 20.600000 CIR S23 20.600000 CIR S25 21.000000 CIR S2622.500000 CIR S27 23.325000 CIR S28 23.325000 CIR S30 26.000000 CIR S3126.000000 CIR S32 24.625000 CIR S33 24.625000 CIR S34 23.325000 CIR S3520.800000 CIR S36 20.800000 CIR S37 23.325000 CIR S38 24.500000 CIR S3924.500000 CIR S40 22.620135 CIR S1 EDG 56.000000 CIR S2 EDG 56.000000CIR S3 EDG 45.000000 CIR S4 EDG 45.000000 CIR S5 EDG 33.500000 CIR S6EDG 33.500000 CIR S7 EDG 29.000000 CIR S8 EDG 29.000000 CIR S10 EDG29.000000 CIR S11 EDG 29.000000 CIR S12 EDG 25.000000 CIR S13 EDG25.000000 CIR S14 EDG 23.500000 CIR S15 EDG 23.500000 CIR S17 EDG23.500000 CIR S18 EDG 23.500000 CIR S20 EDG 22.500000 CIR S21 EDG22.500000 CIR S22 EDG 22.500000 CIR S23 EDG 22.500000 CIR S25 EDG23.000000 CIR S26 EDG 23.000000 CIR S27 EDG 24.500000 CIR S28 EDG24.500000 CIR S30 EDG 27.250000 CIR S31 EDG 27.250000 CIR S32 EDG26.000000 CIR S33 EDG 26.000000 CIR S34 EDG 24.500000 CIR S35 EDG24.500000 CIR S36 EDG 24.500000 CIR S37 EDG 24.500000 CIR S38 EDG26.000000 CIR S39 EDG 26.000000

TABLE 9 Refractive Indices GLASS CODE 620.00 546.00 460.00 SNPH1_OHARA1.802867 1.816450 1.843877 SFPL51_OHARA 1.496049 1.498457 1.502796SLAL18_OHARA 1.727086 1.732342 1.741895 SNBH52_OHARA 1.670317 1.6771931.690210 SNBH53_OHARA 1.734552 1.743423 1.760519 SPHM52_OHARA 1.6164861.620332 1.627325 SLAH66_OHARA 1.770094 1.776215 1.787461 SNBH5_OHARA1.651604 1.658034 1.670170

TABLE 10 EXAMPLE ZOOM DATA Example Zoom Positions POS 1 “WFOV DLP Zoom(25 mm, f/2.5, 45 mm)” POS 2 “WFOV DLP Zoom (27 mm, f/2.5, 45 mm)” POS 3“WFOV DLP Zoom (29 mm, f/2.5, 45 mm)” POS 4 “WFOV DLP Zoom (31 mm,f/2.5, 45 mm)” POS 5 “WFOV DLP Zoom (32 mm, f/2.5, 45 mm)”

TABLE 11 Example Zoom Characteristics POS 1 POS 2 POS 3 POS 4 POS 5 VUYF1 0.2033E−10 0.1793E−10 0.4902E−10 0.7944E−10 0.2927E−11 VLY F10.2033E−10 0.1793E−10 0.4902E−10 0.7944E−10 0.2927E−11 VUY F2 −0.21599−0.18183 −0.15478 −0.13299 −0.12364 VLY F2 −0.19973 −0.16979 −0.14649−0.12288 −0.09459 VUY F3 −0.53249 −0.44066 −0.37057 −0.30906 −0.25788VLY F3 −0.50037 −0.41763 −0.35503 −0.27383 −0.23159 VUY F4 −1.11952−0.89543 −0.68887 −0.48267 −0.39913 VLY F4 −0.50009 −0.57741 −0.57821−0.48305 −0.44152 VUX F1 0.1000E−09 0.1000E−09 0.1000E−09 0.1000E−090.1000E−09 VLX F1 0.1000E−09 0.1000E−09 0.1000E−09 0.1000E−09 0.1000E−09VUX F2 −0.06249 −0.05367 −0.04655 −0.04071 −0.03817 VLX F2 −0.06249−0.05367 −0.04655 −0.04071 −0.03817 VUX F3 −0.13627 −0.11720 −0.10182−0.08919 −0.08371 VLX F3 −0.13627 −0.11720 −0.10182 −0.08919 −0.08371VUX F4 −0.23749 −0.20350 −0.17650 −0.15454 −0.14505 VLX F4 −0.23749−0.20350 −0.17650 −0.15454 −0.14505 THI S9 21.10122 16.39599 12.202348.40022 6.62570 THC S9 100 100 100 100 100 THI S16 14.57457 12.6530710.97057 9.54864 8.92002 THC S16 100 100 100 100 100 THI S24 8.0078011.98483 16.45705 21.53377 24.29253 THC S24 100 100 100 100 100 THI S292.25854 4.90771 6.31204 6.45941 6.10364 THC S29 100 100 100 100 100

TABLE 12 Example Imaging Characteristics POS 1 POS 2 POS 3 POS 4 POS 5INFINITE CONJUGATES EFL 25.0001 27.0002 29.0002 31.0002 32.0002 BFL7.4611 7.4537 7.4781 7.4773 7.4677 FFL 54.7107 54.7102 54.7355 54.775354.7962 FNO 2.4995 2.4996 2.4996 2.4997 2.4997 AT USED CONJUGATES RED0.0020 0.0022 0.0024 0.0025 0.0026 FNO 2.5000 2.5000 2.5000 2.50002.5000 OBJ DIS 12192.0000 12192.0000 12192.0000 12192.0000 12192.0000 TT12488.2561 12488.2556 12488.2560 12488.2560 12488.2559 IMG DIS 7.50607.5060 7.5060 7.5060 7.5060 OAL 288.7501 288.7496 288.7500 288.7500288.7499 PARAXIAL IMAGE HT 22.6200 22.6200 22.6200 22.6200 22.6200 THI7.5122 7.5132 7.5468 7.5557 7.5513 ANG 42.1093 39.9320 37.9351 36.101735.2412 ENTRANCE PUPIL DIA 10.0019 10.8019 11.6018 12.4017 12.8016 THI56.9515 56.7396 56.5398 56.3554 56.2685 EXIT PUPIL DIA 111.5916 143.7111186.4766 243.3103 278.2495 THI −271.4669 −351.7645 −458.6446 −600.7199−688.0723 STO DIA 34.4136 36.3523 38.2632 40.1667 41.1191

INCORPORATION BY REFERENCE

What follows is a cite list of references which are, in addition tothose references cited above and below herein, and including that whichis described as background, the invention summary, brief description ofthe drawings, the drawings and the abstract, hereby incorporated byreference into the detailed description of the preferred embodimentsbelow, as disclosing alternative embodiments of elements or features ofthe preferred embodiments not otherwise set forth in detail below. Asingle one or a combination of two or more of these references may beconsulted to obtain a variation of the preferred embodiments describedin the detailed description below. Further patent, patent applicationand non-patent references are cited in the written description and arealso incorporated by reference into the preferred embodiment with thesame effect as just described with respect to the following references:

-   U.S. Pat. Nos. 5,973,826, 6,033,079, 6,072,852, 6,147,818,    6,183,095, 6,188,513, 6,226,346, 6,262,836, 6,318,869, 6,426,506,    6,636,350, 6,864,861, 6,906,866, 6,927,901, 6,985,210, 7,009,140,    7,061,959, 7,085,075, 7,151,592, 7,190,527, 7,190,530, 7,199,922,    7,218,445, 7,237,915, 7,355,678, 7,375,798, 7,382,540, 7,450,301,    7,508,581, 7,859,748, 7,884,303, 8,362,391, and RE42,118.

The following documents are also incorporated by reference:

-   ANSI/NAPM IT7.228-1997 American National Standard for Audio Visual    Systems, Electronic Projection—Fixed Resolution Projectors-   FPDM, 6/1/01 VESA Flat Panel Display Measurements Standard, V2.0-   Mil-Std-810F Test Method for Environmental Engineering    Considerations and Laboratory Tests-   MIL-PRF-13830B Optical Components for Fire Control Instruments-   MIL-C-675 Reflection-Reducing Films for Glass Optical Elements

While an exemplary drawings and specific embodiments of the presentinvention have been described and illustrated, it is to be understoodthat that the scope of the present invention is not to be limited to theparticular embodiments discussed. Thus, the embodiments shall beregarded as illustrative rather than restrictive, and it should beunderstood that variations may be made in those embodiments by workersskilled in the arts without departing from the scope of the presentinvention.

In addition, in methods that may be performed according to preferredembodiments herein and that may have been described above, theoperations have been described in selected typographical sequences.However, the sequences have been selected and so ordered fortypographical convenience and are not intended to imply any particularorder for performing the operations, except for those where a particularorder may be expressly set forth or where those of ordinary skill in theart may deem a particular order to be necessary.

A group of items linked with the conjunction “and” in the abovespecification should not be read as requiring that each and every one ofthose items be present in the grouping in accordance with allembodiments of that grouping, as various embodiments will have one ormore of those elements replaced with one or more others. Furthermore,although items, elements or components of the invention may be describedor claimed in the singular, the plural is contemplated to be within thescope thereof unless limitation to the singular is explicitly stated orclearly understood as necessary by those of ordinary skill in the art.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other such as phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “assembly” does not imply that the components or functionalitydescribed or claimed as part of the assembly are all configured in acommon package. Indeed, any or all of the various components of aassembly, e.g., optical group 1 and optical group 2, may be combined ina single package or separately maintained and may further bemanufactured, assembled or distributed at or through multiple locations.

Different materials may be used to form the lenses of the opticalassemblies of the several embodiments. For example, various kinds ofglass and/or transparent plastic or polymeric materials may be used.

What is claimed is:
 1. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein the third optical group comprises a doublet or a quasi-doublet or both, wherein the third optical group includes a meniscus and a biconvex lens.
 2. The projection zoom lens assembly of claim 1, wherein the first movable zoom group is movable relative to each of the first and third optical groups and the third zoom group.
 3. The projection zoom lens assembly of claim 2, wherein the second movable zoom group is movable relative to the first movable zoom group, the first and third optical groups, and the third zoom group.
 4. The projection zoom lens assembly of claim 1, wherein the first optical group comprises a first lens having a largest diameter among zoom lenses.
 5. The projection zoom lens assembly of claim 4, wherein the first optical group comprises a second lens having a second largest diameter.
 6. The projection zoom lens assembly of claim 5, wherein each of the lenses of the second and third optical groups have approximately a same diameter which is smaller than the diameters of the first and second lenses of the first optical group.
 7. The projection zoom lens assembly of claim 1, wherein the second movable zoom group comprises an aperture stop.
 8. The projection zoom lens assembly of claim 7, wherein the aperture stop is disposed between a doublet and a singlet of the second movable zoom group.
 9. The projection zoom lens assembly of claim 1, wherein each of the zoom optical groups comprises a singlet spaced from a doublet or a quasi-doublet.
 10. The projection zoom lens assembly of claim 1, wherein a first adjustable spacing is defined between the first optical group and the first movable zoom group, a second adjustable spacing is defined between the first movable zoom group and the second movable zoom group, and a third adjustable spacing is defined between the second movable zoom group and the third zoom group.
 11. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 1. 12. The digital cinema projection system of claim 11, wherein the first movable zoom group is movable relative to each of the first and third optical groups and the third zoom group.
 13. The digital cinema projection system of claim 12, wherein the second movable zoom group is movable relative to the first movable zoom group, the first and third optical groups, and the third zoom group.
 14. The digital cinema projection system of claim 11, wherein the first optical group comprises a first lens having a largest diameter among zoom lenses.
 15. The digital cinema projection system of claim 14, wherein the first optical group comprises a second lens having a second largest diameter.
 16. The digital cinema projection system of claim 15, wherein each of the lenses of the second and third optical groups have approximately a same diameter which is smaller than the diameters of the first and second lenses of the first optical group.
 17. The digital cinema projection system of claim 11, wherein the second movable zoom group comprises an aperture stop.
 18. The digital cinema projection system of claim 17, wherein the aperture stop is disposed between a doublet and a singlet of the second movable zoom group.
 19. The digital cinema projection system of claim 11, wherein the third optical group comprises a doublet or a quasi-doublet or both.
 20. The digital cinema projection system of claim 11, wherein each of the zoom optical groups comprises a singlet spaced from a doublet or a quasi-doublet.
 21. The digital cinema projection system of claim 11, wherein a first adjustable spacing is defined between the first optical group and the first movable zoom group, a second adjustable spacing is defined between the first movable zoom group and the second movable zoom group, and a third adjustable spacing is defined between the second movable zoom group and the third zoom group.
 22. The digital cinema projection system of claim 11, wherein said third zoom group comprises a fixed zoom group.
 23. The projection zoom lens assembly of claim 1, wherein said third zoom group comprises a fixed zoom group.
 24. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits axial chromatic aberrations less than 20 microns.
 25. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 24. 26. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits lateral chromatic aberrations less than 0.75 pixels.
 27. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 26. 28. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits lateral chromatic aberrations less than 0.5 pixels.
 29. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 28. 30. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits distortion at 0.75 field of less than 2.5%.
 31. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 30. 32. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits distortion at 0.95 field of less than 2.0%.
 33. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 32. 34. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits a throw ratio range between 0.8-1.1.
 35. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 34. 36. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits a color transmission differential of less than 8%.
 37. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 36. 38. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits a total light transmission of greater than 90%.
 39. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 38. 40. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein said projection zoom lens assembly exhibits a focus drift of less than 5 microns/20° C.
 41. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 40. 42. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein the lens assembly is configured to focus from infinity to 25 feet.
 43. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 42. 44. A projection zoom lens assembly for a digital cinema projection system, comprising: a first optical group including one or more wide angle lenses for projecting digital cinema images; a second optical group including a set of zoom optical groups each comprising two or more lenses, including: a first independently movable zoom group; a second independently movable zoom group; and a third zoom group; and a third optical group including multiple lenses for receiving images for projection, wherein the lens assembly is configured such that a rotational torque of the projection zoom lens is less than 0.5 N-m.
 45. A digital cinema projection system, comprising: a relay lens assembly, and a projection zoom lens assembly as recited in claim
 44. 